Chemical substances are often called 'pure' to set them apart from mixtures. A common example of a chemical substance is pure water; it has the same properties and the same ratio of hydrogen to oxygen whether it is isolated from a river or made in a laboratory.
It acts to replace and recover from the activities of living. Its action is (almost always) the opposite of the sympathetic division. It activates the gut for digestion, slows the heart rate, decreases the blood pressure, etc. The autonomic nervous system controls the insides of the body: the viscera or gut.
The subdivisons of the autonomic system are the _____ division and _____ division. sympathetic/ parasympathic. In response to a specific stimulus, autonomic reflex arcs can trigger the following responses: Smooth muscle contraction. Secretion by glands. Skeletal muscle contraction. Cardiac muscle contraction.